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As a data point, my wiring splice looked factory and was professional (attached). Replacing my spark plugs improved my idle and misfires.
I was having a rough idle and misfires (but no codes) and did many of the usual services to try to improve it (rebuild intake, new coil, new MAFs etc.) After seeing this thread I applied crimp pressure and heat to the splice just incase the solder didn't fully penetrate into the wiring from the factory, this had no affect on the idle and misfires.
I did not initially replace the plugs, which seems dumb, but the Carfax on my 2011 E63 indicated the plugs were replaced 5000 miles prior. I did not think they would be bad in that short period of time, and I did pull a couple to inspect. They looked fine visually and the gap seemed close (.040-.042)
Later I went ahead and bought a set of new NGK spark plugs and this time carefully measured the gap of all eight old ones. Some were acceptable at around .040-.042 while others were way out of spec at .50-.052+.
New plugs improved the idle by about 90% and a custom tune by Eighty Six Tuned helped a little more, probably because my car has VRP cams but with no aftermarket tune previously.
MTBSully probably has a different issue but I wanted to post a photo of my splice and experience for anyone else with similar issues.
Good data point, thanks for sharing. I have been hesitant to rip my wiring harness sheathing completely apart to replace the sheathing but it might come to that if I can't figure this out.
Working with my picoscope now gathering cam and crank signals. Still need to look at the data closer, but nothing jumping out as abnormal yet.
Also unplugged my knock sensors to rule out some weird false knock causing this. No change, car still misfires and goes into limp mode at 1500RPM.
Finally had some time the last few nights to gather some data. Slow progress, still not sure if I have found anything.
Got my picoscope working, compared cam+crank signals from both intake and exhaust from bank 1 to bank 2: Nothing seems out of the ordinary, not an expert at interpreting the data but both sides seem to match.
Inspected wiring, started cutting open sheathing, nothing jumping out yet. Some of my injectors have cracks where the wires entered the injector plug. Applied liquid electrical tape, no change.
Got out my scanner and started inspecting cam position data at idle and at 1500RPM. What is interesting is what my scanner is showing as "Intake camshaft of left cylinder bank" seems to be all over the place (blue line) and completely out of control. This would be a smoking gun if it was on bank one, where the misfires are, or what I would consider to be the "right cylinder bank". Unless this Chinese scanner has the banks backwards?
Why is the cam position all over the place on the "left cyinder bank" when all of my misfires are on bank 1?
Still keep coming back to an issue with the adjusters somehow, even though I've gone through them like twice now. Might even swap the adjusters bank to bank to see if possibly one component on the adjuster is bad.
Finally had some time the last few nights to gather some data. Slow progress, still not sure if I have found anything.
Got my picoscope working, compared cam+crank signals from both intake and exhaust from bank 1 to bank 2: Nothing seems out of the ordinary, not an expert at interpreting the data but both sides seem to match.
Inspected wiring, started cutting open sheathing, nothing jumping out yet. Some of my injectors have cracks where the wires entered the injector plug. Applied liquid electrical tape, no change.
Got out my scanner and started inspecting cam position data at idle and at 1500RPM. What is interesting is what my scanner is showing as "Intake camshaft of left cylinder bank" seems to be all over the place (blue line) and completely out of control. This would be a smoking gun if it was on bank one, where the misfires are, or what I would consider to be the "right cylinder bank". Unless this Chinese scanner has the banks backwards?
Why is the cam position all over the place on the "left cyinder bank" when all of my misfires are on bank 1?
Still keep coming back to an issue with the adjusters somehow, even though I've gone through them like twice now. Might even swap the adjusters bank to bank to see if possibly one component on the adjuster is bad.
The saga continues....
Is it possible that the intake adjuster isn't getting oil pressure, and ipso facto can't advance or retard timing as necessary?
Last edited by Big Worm; Dec 18, 2025 at 02:50 PM.
Update: Took the top end apart again to do a couple of things:
Replace cam sealing rings with the new Menehker plastic ones
Swap cam adjusters from bank 1 to bank 2 and vice versa
Double check timing
Got it all back together, you guessed it, still misfiring on bank 1. No matter what I do, it seems I can't get the misfires to move off of bank 1. At this point, we know its not the cam adjusters.
I'm starting to wonder if its an oil pressure issue on that head that is causing low pressure to the adjusters or something. I have an extra cam adjuster cover, might try and drill and tap it and see if there is a difference between intake and exhaust, or bank 1 to bank 2. Not sure if this has ever been done, or if there is a better way to go about this.
The only reason I am wondering about this is because way back when I did my head bolts/lifters, i broke the front most cam cap bridge upon re-assembly. I know these are usually machined with the head but I grabbed one off of ebay and put it in and it seemed fine, and the car ran perfect for 10,000 miles. But is it possible the clearance is not correct and now this is showing up? Just grasping at straws here but would love to verify an oil pressure issue at the adjusters before I start sourcing a new head and pulling the motor apart for nothing.
Just watched the newest video last night. Was hoping to see a nice conclusive effort to this AMG saga, but this sort of thing is all part of the fun.
Apologies if I missed it, but the cam adjuster cover has not been replaced right? Your issue persists on bank 1 regardless of which cam adjusters are used. The issue is also resolved when the cam adjuster solenoid is not connected suggesting that the top end if probably fine. So if the adjusters themselves aren't the issue and the entire bank runs perfect with the solenoid unplugged, it would lead me to believe theres an issue within the cam adjuster cover. The cover contains oil passages and sealing interfaces to route pressurized oil via the solenoid. Given that the issue only arises above 1500rpm, there could be an issue within the cam adjuster cover related to oil pressure, sealing, or routing.
Hope this helps. Been watching your channel for a while and these E63 videos have helped me immensely with my 2011.
Update: Took the top end apart again to do a couple of things:
Replace cam sealing rings with the new Menehker plastic ones
Swap cam adjusters from bank 1 to bank 2 and vice versa
Double check timing
Got it all back together, you guessed it, still misfiring on bank 1. No matter what I do, it seems I can't get the misfires to move off of bank 1. At this point, we know its not the cam adjusters.
I'm starting to wonder if its an oil pressure issue on that head that is causing low pressure to the adjusters or something. I have an extra cam adjuster cover, might try and drill and tap it and see if there is a difference between intake and exhaust, or bank 1 to bank 2. Not sure if this has ever been done, or if there is a better way to go about this.
The only reason I am wondering about this is because way back when I did my head bolts/lifters, i broke the front most cam cap bridge upon re-assembly. I know these are usually machined with the head but I grabbed one off of ebay and put it in and it seemed fine, and the car ran perfect for 10,000 miles. But is it possible the clearance is not correct and now this is showing up? Just grasping at straws here but would love to verify an oil pressure issue at the adjusters before I start sourcing a new head and pulling the motor apart for nothing.
Just watched your latest video and I appreciate your content.
Hang in there. The solution is out there.
This technically is possible, but if disconnecting the solenoid "resolves" the misfire, it suggests that your root cause is electrical, not mechanical (although the timing being off that much was something of note).
Before pulling the engine apart, I agree with one of the more detailed commenters on the video and would advise checking everything electrical / in the wiring harness first.
As that commenter stated, MB is notorious for having oil wicking up into the most unbelievable of places (e.g. 722.6 trans connector, misc. connectors in the engine, etc.) across a number of platforms, and the fact that there's a tech. bulletin out for this on the M156 / M159 makes it a worthwhile next step, IMHO.
Good luck and looking forward to the "I FINALLY FIXED MY AMG!" video.
I picked up a spare engine harness just to have it about 9 months ago. After hours of checking the harness, peeling back insulation, checking for oil etc. and finding nothing, I finally said "screw it" and installed the spare engine harness. Pretty tight space while leaving my original harness in place, but I got it done.
You guessed it, car still does the EXACT same thing. So it appears it is not a wiring/harness issue either.
At this point I think im going to pull the cams on this side and inspect bearing caps/ clearances and see if anything jumps out.
I appreciate your dogged determination on this! Have you swapped cam adjusters, and/or camshafts, from Bank 1 to 2, to see if the error follows? I know that you have done just about everything to eliminate electrical and mechanical causes, and chasing oil pressure/clearances starts to make sense. I just do not know of a good way to check that, especially since it only seems to be an issue at 1,500rpm and fine everywhere else.
I appreciate your dogged determination on this! Have you swapped cam adjusters, and/or camshafts, from Bank 1 to 2, to see if the error follows? I know that you have done just about everything to eliminate electrical and mechanical causes, and chasing oil pressure/clearances starts to make sense. I just do not know of a good way to check that, especially since it only seems to be an issue at 1,500rpm and fine everywhere else.
The only think i havent swapped is the cams themselves. Are they the same from bank to bank? I think they are. I have already swapped the adjusters from bank 1 to bank 2 and vice versa with no change.
The only think i havent swapped is the cams themselves. Are they the same from bank to bank? I think they are. I have already swapped the adjusters from bank 1 to bank 2 and vice versa with no change.
Need to verify with WIS but from top of mind, yes they are just 'intake' and 'exhaust' camshafts and not bank dependent. Was your plan to pull the cam caps and do plastigauge?
Need to verify with WIS but from top of mind, yes they are just 'intake' and 'exhaust' camshafts and not bank dependent. Was your plan to pull the cam caps and do plastigauge?
*CORRECTION: they are bank specific, nevermind.
Good info thanks. Yes, might check the clearance on the front most cam "bridge" since that is the only thing I have changed. I dont see any spec from MB on what camshaft cap clearance should be, so I guess I will just have to compare to drivers bank and/or see what most DOHC engines use for camshaft clearance.
Might be time for a Tasos and CS collab over this!
I am unsure the exact path the oil is fed into the solenoid/adjuster to regulate pressure and timing adjustment, but it would need to be fed from the cam covers, into the camshaft, and then into the adjusters and then solenoids for the clearances of the cam covers to matter. Seems to me the adjusters and solenoids would be fed from the front of the engine, but that is just my guess.
Might be time for a Tasos and CS collab over this!
I am unsure the exact path the oil is fed into the solenoid/adjuster to regulate pressure and timing adjustment, but it would need to be fed from the cam covers, into the camshaft, and then into the adjusters and then solenoids for the clearances of the cam covers to matter. Seems to me the adjusters and solenoids would be fed from the front of the engine, but that is just my guess.
I messaged Tasos over a year ago on IG, never got a response. If anyone knew where to look, it would probably be him.
Based on my inspection, it looks like pressure comes up through the block, into the heads, into the cam bores/caps, into the cams, and then into the adjusters. Also looks like there is oil ports in the solenoid covers as well, not sure where those fit in.
Really HATE to potentially have to take the head off, and would love to find a "smoking gun" before doing so. But said smoking gun on this issue has eluded me for 2 years.
I messaged Tasos over a year ago on IG, never got a response. If anyone knew where to look, it would probably be him.
Based on my inspection, it looks like pressure comes up through the block, into the heads, into the cam bores/caps, into the cams, and then into the adjusters. Also looks like there is oil ports in the solenoid covers as well, not sure where those fit in.
Really HATE to potentially have to take the head off, and would love to find a "smoking gun" before doing so. But said smoking gun on this issue has eluded me for 2 years.
As someone who's removed the heads from my m156 too many times, I can agree with that sentiment and I also do not see any benefit you would have doing it. The only issue I would see at that point is an plugged/blocked oil port and the ones through the heads are pretty large and feels like there would be an oil pressure issue across the entire range. If I remember from your videos, you have an oil gauge on your oil filter housing....have you noticed the pressure doing anything funky at 1500rpm vs other times?
As someone who's removed the heads from my m156 too many times, I can agree with that sentiment and I also do not see any benefit you would have doing it. The only issue I would see at that point is an plugged/blocked oil port and the ones through the heads are pretty large and feels like there would be an oil pressure issue across the entire range. If I remember from your videos, you have an oil gauge on your oil filter housing....have you noticed the pressure doing anything funky at 1500rpm vs other times?
I haven't checked oil pressure at 1500rpm yet, since i'll need someone to rev the car while I look, or maybe I can use my camera. Oil pressure is normal at idle and cold start though.
I haven't checked oil pressure at 1500rpm yet, since i'll need someone to rev the car while I look, or maybe I can use my camera. Oil pressure is normal at idle and cold start though.
I do not see how if you have an oil pressure issue at 1500 it wouldn’t affect both banks, but I think it’s worth a shot at this point. The oil pumps are MASSIVE on the m156’s…so if it is oil pressure related, it feels like it would be localized to somewhere around the cam adjuster/solenoids on that bank.
I do not see how if you have an oil pressure issue at 1500 it wouldn’t affect both banks, but I think it’s worth a shot at this point. The oil pumps are MASSIVE on the m156’s…so if it is oil pressure related, it feels like it would be localized to somewhere around the cam adjuster/solenoids on that bank.
I think we are in agreement. I know my overall oil pressure is well within spec. I think if anything, it is a localized oil pressure issue on that bank that is not allowing the solenoids to correctly/precisely control the cams at that RPM. Hence my theory that the cam bridge clearance is out of spec and/or somehow the cam is out of round and there is a weird resonance at 1500rpm.
Yeah, I think you have done a great job showing it’s not electrical related (unless there’s something REALLY weird with the tune at that RPM), and you’ve swapped all the parts over that you can and the error did not follow so I agree that it’s a very weird oil/mechanical issue.
I think we are in agreement. I know my overall oil pressure is well within spec. I think if anything, it is a localized oil pressure issue on that bank that is not allowing the solenoids to correctly/precisely control the cams at that RPM. Hence my theory that the cam bridge clearance is out of spec and/or somehow the cam is out of round and there is a weird resonance at 1500rpm.
This is a good theory, but might be worthwhile to verify no internal obstructions within the cam adjuster cover/housing. You're seeing overall oil pressure within spec and you're not having pressure issues with the solenoid unplugged. This probably means lower likelihood of an obstruction in the head. You could test oil pressure across the range with the solenoid unplugged which could point you to the housing. It's very possible that there could be a small blockage in the housing that has no effect under 1500rpm, but once you go above that, the potential blockage is restricting the oil pressure needed to correctly control the cam adjusters. As both you and @6_Myles said, taking the heads off would really suck and should be saved for a last resort.
This is a good theory, but might be worthwhile to verify no internal obstructions within the cam adjuster cover/housing. You're seeing overall oil pressure within spec and you're not having pressure issues with the solenoid unplugged. This probably means lower likelihood of an obstruction in the head. You could test oil pressure across the range with the solenoid unplugged which could point you to the housing. It's very possible that there could be a small blockage in the housing that has no effect under 1500rpm, but once you go above that, the potential blockage is restricting the oil pressure needed to correctly control the cam adjusters. As both you and @6_Myles said, taking the heads off would really suck and should be saved for a last resort.
Thanks for the feedback. I think we can rule out the adjusters as a whole though for a couple of reasons:
I have taken apart, inspected, and rebuilt the adjusters at least 2 times since this issue surfaced. The latest time to include 63 motorsports skeleton covers and titanium hardware. No issues to be seen.
I recently swapped the bank 1 adjusters (where the misfires are) over to bank 2. The misfires did not move from bank 1. No change at all in how the car behaves.
My theory is less of an oil pressure obstruction, and more of an excessive oil pressure bleedoff due to incorrect clearances on the replacement camshaft bridge and the camshaft. Increased clearance = less oil pressure making its way to adjusters = solenoids cannot properly control adjusters = misfires.
All just a theory, but (again) i'm running out of things this could possibly be lol.
Thanks for the feedback. I think we can rule out the adjusters as a whole though for a couple of reasons:
I have taken apart, inspected, and rebuilt the adjusters at least 2 times since this issue surfaced. The latest time to include 63 motorsports skeleton covers and titanium hardware. No issues to be seen.
I recently swapped the bank 1 adjusters (where the misfires are) over to bank 2. The misfires did not move from bank 1. No change at all in how the car behaves.
My theory is less of an oil pressure obstruction, and more of an excessive oil pressure bleedoff due to incorrect clearances on the replacement camshaft bridge and the camshaft. Increased clearance = less oil pressure making its way to adjusters = solenoids cannot properly control adjusters = misfires.
All just a theory, but (again) i'm running out of things this could possibly be lol.
Just to clarify.
You are fully right in conclusively ruling out the cam adjusters themselves since you've rebuilt them at least twice and have also swapped them between banks with no change in the misfire.
I'm referring to the housing that the cam adjusters and the solenoid interface with. See pic below. Part number 1560500118
My theory is that some sort of oil passage within this housing may be damaged or obstructed. Which may be why the car runs perfect with the solenoid unplugged, but when plugged in the issue arises.
Your theory on excessive oil pressure bleedoff due to incorrect clearances is great, but I figured this is a relatively inexpensive part that could save you $ before you start digging deeper into the cams or head.
You are fully right in conclusively ruling out the cam adjusters themselves since you've rebuilt them at least twice and have also swapped them between banks with no change in the misfire.
I'm referring to the housing that the cam adjusters and the solenoid interface with. See pic below. Part number 1560500118
My theory is that some sort of oil passage within this housing may be damaged or obstructed. Which may be why the car runs perfect with the solenoid unplugged, but when plugged in the issue arises.
Your theory on excessive oil pressure bleedoff due to incorrect clearances is great, but I figured this is a relatively inexpensive part that could save you $ before you start digging deeper into the cams or head.
Ahhh, I see. yes, I had this same theory about a year ago. I replaced the housing with a good used one, including cam sensors and solenoids, installed, and no change.
Ahhh, I see. yes, I had this same theory about a year ago. I replaced the housing with a good used one, including cam sensors and solenoids, installed, and no change.
No easy fix on this thing
Haha damn. Was hoping it was something as easy as this.
Good luck brother. Lookin forward to seeing this AMG fully healed up. 👍
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